Currently, a plurality of information processing apparatuses such as computers are connected to a network and data communication is performed between the apparatuses via the network. The communication path of the network may include a wired section transmitting a signal by wire and a wireless section transmitting a signal by radio. Further, TCP/IP (Transmission Control Protocol/Internet Protocol) is employed as a protocol for transmitting data on the network. Transmission and reception of packetized data are performed widely using TCP/IP.
Meanwhile, a situation of the data communication in the network is sometimes analyzed in order to improve data communication setting or the like. For example, there has been a proposal to measure a packet round-trip time in a communication path including a radio communication section, estimate a communication speed from the maximum value and the minimum value of variation in the round-trip time, and calculate a re-transmission timeout time adapted for a transmission data length based on the estimated value.
Further, when a communication apparatus communicates with an opposite apparatus via a relay apparatus, there is also a proposal to switch the communication with the opposite apparatus from the indirect radio communication via the relay apparatus to direct radio communication without passing through the relay apparatus, if the communication section between the relay apparatus and the opposite apparatus is determined to be a radio connection. In this proposal, the relay apparatus and the opposite apparatus are determined to be connected by radio when the communication apparatus and the relay apparatus are connected by radio and the communication time between the relay apparatus and the opposite apparatus is longer than the communication time between the communication apparatus and the relay apparatus.
Japanese Laid-Open Patent Publication No. 2004-253934
Japanese Laid-Open Patent Publication No. 2010-161616
The data communication situation is sometimes analyzed in a system in which a server apparatus provides service to a plurality of client terminals. In particular, analyzing communication delay in a wireless section of the communication including the wireless section in the communication path may lead to improvement of a communication quality and the like for a radio terminal.
Here, comparatively many wireless sections exist within the network in a user-side network end section (downstream side) connecting a client terminal and a radio access point, for example. Accordingly, when a packet collection apparatus is installed in each of the wireless sections, the number of collection points is increased and the number of the apparatuses to be installed is also increased. Therefore, it is conceivable to collect packets in the wired section to which the server apparatus is connected (upstream side). This is because it is possible to effectively collect packets transmitted and received between the server apparatus and the plurality of client terminals with a smaller number of collection points than on the downstream side.
In this case, the packets to be collected are not limited to just the packets of the communication including the wireless section in the communication path. For example, when the server apparatus provides services for many and unspecified client terminals, the packets to be collected may include also packets of the communication not including a wireless section in the communication path between the server apparatus and the client terminal. Accordingly, it becomes a problem how to select the packets of the communication including the wireless section from the collected packets.